alternator housing cracked

Falk930 · 11:10 AM

During some work on my `87 930 I noticed a small hair crack in the alternator housing.
Safety first I decided to uninstall the alternator incl. housing.
This is what I found:
2 cracked fins at 9+12 o`clock position.

additionally, this is how the housing looks
where the alternator should fit inside:
Same on both locations with cracked fins.

It was difficult to pull the alternator out!

When I noticed the hair crack from outside, I was thinking
its a age related issue, maybe forced from bad alternator bearing.
The alternator has small play only.

But these 2 cracked fins and the deformations on the inside
seem more the result from something hitting the housing from outside.

Anyone here experienced something similar?

I need a alternator/fan housing, any offers welcome!!

*do I need the special turbo housing or can I use
a Carrera one?

thanks for help
Falk

rsrmike · 11-19-2008, 12:32 PM

The alternators are always a very tight fit. It's best to use a press of some sort and gently press them out from the back just a few milimeters at a time, working your way around the mounting studs.

Perhaps someone was too agressive at somepoint either removeing or installing the alternator for repair? I think the carrera uses the same alt. and housing.

Also, the torque spec for the mounting stap is extremely low, much lower then what feels "right" perhaps it was overtorqued at some point. use very light torque when reassembling. Basically, just enough to keep the bolt from backing out, a little loctite wouldn't be bad idea either...

rsrmike · 11-19-2008, 12:33 PM

I wish I has a housing to send you, hopefully someone can help...

Good luck

sand_man · 11-19-2008, 12:41 PM

Quote:

Originally Posted by rsrmike

The alternators are always a very tight fit. It's best to use a press of some sort and gently press them out from the back just a few milimeters at a time, working your way around the mounting studs.

Perhaps someone was too agressive at somepoint either removeing or installing the alternator for repair? I think the carrera uses the same alt. and housing.

Also, the torque spec for the mounting stap is extremely low, much lower then what feels "right" perhaps it was overtorqued at some point. use very light torque when reassembling. Basically, just enough to keep the bolt from backing out, a little loctite wouldn't be bad idea either...

I use the "John Walker gravity method" for removing the alternator from the fan housing:
http://forums.pelicanparts.com/showthread.php?t=60368

A930Rocket · 11-19-2008, 01:27 PM

I think it might be normal. When I had mine powder coated, the guy said it was all cracked up. I came back to look at it and it was just like it always was.

My thinking is that it's the porosity if the magnesium material. At least I think it's magnesium.

Vertex Auto has them as re-productions. DC Auto problably has used ones.

DailyDriven'88 · 11-19-2008, 02:26 PM

I had mine rewelded at a local welding shop that does subcontracted aerospace work. The housing is a magnesium alloy. I dont know what filler rod they used but $75 later and its still holding up good after about 30k miles.

Also, as someone else already stated, dont overtighten the strap when reinstalling. I did a tad tighter than hand tight and used blue loctite.

So how are those vertex auto ones?

William930t · 11-19-2008, 07:08 PM

My alternator/fan housing was cracked similar to yours and caused the fan blades to rub. This is typical of magnesium deterioration over time. I went the Vertex route. After grinding off the Vertex logo, adding primer and paint, plus some wrestling to fit in place I am generally pleased. Original housing is extremely light. Vertex is heavy and strong, but I don't ever have to worry about this unit cracking.